This invention relates to a vehicle suspension adjustment device, and in particular, to a positive shim locking system used in a vehicle suspension adjustment device.
Conventional vehicle suspensions may include shims, or spacers, to adjust the position of a suspension control arm to control wheel camber and/or caster. One conventional system for adjusting wheel camber and wheel caster includes a pivot shaft that extends in a fore/aft direction of the vehicle between two branches of a control arm. Two mounting bolts extend through a pair of support members of the vehicle frame and through the pivot shaft along transverse axes perpendicular to the longitudinal axis of the shaft. Shims are disposed on each bolt between the pivot shaft and support members. Adding or removing shims on either bolt enables adjustment of wheel caster. Adding or removing equal numbers of shims from both bolts enables adjustment of wheel camber.
Although this adjustment system enables adjustment of both wheel camber and caster, the system suffers from several disadvantages. First, caster adjustment also results in adjustment of camber (i.e., the adjustment is not independent). Second, the addition or removal of shims requires storage and maintenance of the shims. Finally, the system requires a relatively large amount of time to make desired adjustments because the mounting bolts must be removed to add or remove the shims. Some inventive systems have attempted to overcome this difficulty by using shims with open-ended slots. The shims in these systems, however, frequently work lose during operation of the vehicle becoming unseated from the mounting bolts and/or misaligned relative to one another.
There is thus a need for a suspension adjustment device that will minimize or eliminate one or more of the above-mentioned deficiencies.
The present invention provides an improved suspension adjustment device.
A suspension adjustment device in accordance with the present invention includes a fastener disposed about a longitudinal axis. The fastener extends through a pair of support members of a vehicle frame, and a suspension control arm. The inventive system further includes a shim pack disposed between one support member and the control arm. The shim pack includes a shim having an open-ended slot configured to receive the fastener. The shim pack further includes another shim coupled to the open-ended shim. The shim pack may further include a pair of ring shaped members disposed about the fastener, and coupled to the shims. The addition or removal of coupled shims adjusts the position of the suspension control arm relative to the vehicle frame. The inventive system may further include a second shim pack disposed between the other support member and the control arm. Adjustment of the control arm position may be made by swapping shims between the shim packs.
A suspension adjustment device in accordance with the present invention has several advantages as compared to conventional systems. The inventive device allows wheel caster adjustment independently from wheel camber adjustment. The inventive device allows much faster and less cumbersome adjustment of wheel caster while preventing the shims from working loose and/or becoming dislodged. Additionally, the shims in the inventive device stay locked regardless of the position set for camber or caster. Finally, when two shim packs are used on opposite sides of the control arm, all the shims needed for adjustment may be found within the inventive device as adjustments may be made by swapping shims between the first and second shim packs.
These and other features and objects of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawing illustrating features of this invention by way of example.